We knew Microsoft was planning big things for MIX10, which started today. There are quite a few announcements from the blogosphere today, including developer tools, Marketplace news, etc. Read on for more details!

First, according to Endgadget, the only official way to get apps on a Windows Phone 7 Series device is through the Marketplace app. In a meeting with Todd Higgs, he confirmed this rumor, which means that all developers will have to follow Microsoft’s guidelines to get published. Sound familiar? Very Apple-like if you ask us. While this is the only “official” way to get apps, that doesn’t rule out the fact that there may be “unofficial” ways to do it too. According to Todd, Microsoft plans on avoiding the headaches like Apple head by making the process transparent and predictable.

  • Windows Phone Marketplace appears to take some of the best parts of the App Store and the Android Market and throw them together into a hodgepodge, but they’ve strayed a bit with the trial period system — with the Marketplace, it’s up to the developer to decide how the trial works. There are API hooks to let the developer manage the whole process, actually — to quote Biggs, a game dev could end the trial after you’ve killed 50 trolls, for example. There’s no additional download after the trial expires; the game just unlocks if you choose to buy it.
  • Marketplace membership for developers still costs $99 a year, though Biggs says they’re looking at tweaking the 5-app limit per account present in 6.5 — whether that means they’ll remove the limit altogether, though, we don’t yet know.
  • There are no fees for developers to update their apps, nor fees for users to download them.
  • Speaking of user downloads, you’ll be able to uninstall purchased apps and redownload them at a later time at your leisure — the purchases are tied to your Live account, not your phone, so you can move between devices at will. That’s a Microsoft policy that developers won’t be able to override.
  • If a dev wants to post a free, ad-supported app, they’ve only got two hurdles: the $99 fee and — of course — approval by Microsoft. For ad-supported apps specifically, the company will have some guidelines specifically targeted at making sure the ads are appropriate and germane.
  • Microsoft’s only dealing in real money here — no points (though there’s still an opportunity for direct carrier billing).
  • Though there’s some development synergy between Zune and WP7S at this point (with XNA, specifically), there’s no ecosystem synergy beyond that — different marketplaces for the developers to submit to and manage.
  • You’ll be able to browse and buy apps and games through the Zune client.

According to Gizmodo, Microsoft’s Marketplace Partners include Pandora, Foursquare, EA Mobile, AP, and more.

According to MobileTechWorld, Microsoft’s development tools for Windows Phone 7 is available for download now.

According to WMExperts, Microsoft has also released a carrier’s worst nightmare, Netflix Streaming! You can also manage your queue and browse their catalog, but the live streaming is huge. We wonder if carriers will try to make this a WiFi only feature.

Slashgear has reported on a new feature, which reminds us of Android, and that’s push notifications. Even apps that aren’t running in the background can use the new system, which has a blue scrolling bar across of the top of the device.

WMExperts is also highlighting Microsoft’s huge use of using Silverlight 4 in the new Windows Phone 7 Series.

  • Hardware-accelerated video with multicodec digital rights management (DRM) and Internet Information Services Smooth Streaming support
  • Vector and bitmap graphics with perspective 3-D
  • Multitouch support with Accelerometer, an intuitive control that responds to motion
  • Deep Zoom support for rich reading experiences
  • Camera and microphone support
  • Notification Service for pushing information to the phone, regardless of whether or not an application is running
  • Integration with the core Windows Phone 7 Series experience features such as hubs

IntoMobile has just posted a picture of the second known Windows Phone 7 device, made by Samsung! We’re not sure where the HTC devices are, but so far we have seen a LG device and now a Samsung one, which was shown during Joe Belfiore’s UI demo.

GSMArena has released the hardware requirements for Windows 7 Phones. At launch, the only available resolution will be WVGA (480×800) with HVGA (320×480) being available later. They will be required to have capacitative touchscreens. Hardware keyboard is optional. The CPU needs to have a Cortex or Scorpion, which is inside the Snapdragon. At least 256Mb of RAM and at least 8Gb of flash storage (rumors are that there will be no external storage, so no more memory cards). There is also mandatory GPU acceleration and DirectX support. It will also natively support DivX and H.264. The camera has to be a minimum 5MP with a hardware shutter key and LED flash. Other requirements include A-GPS, compass, accelerometer, ambient light and proximity sensor. The other three required hardware keys are Start, Search and Back.

Also, it has been confirmed that the HD2 will not be getting an upgrade.